Fluorescent lighting tubes are commonly used in a large range of lighting systems as a result of advantages such as longer life time and better luminous efficiency compared to incandescent lamps. However, in the continuous effort to reduce power consumption, it is desirable to replace conventional light tubes with still more energy efficient and environmental friendly alternatives. One such alternative is to use LED tubular light sources having a plurality of LED's arranged in a tube similar to the fluorescent tube. In order to facilitate a transition from fluorescent tube lights to LED tubular light sources, the LED tubular light sources should be configured to be mounted in already existing fixtures for fluorescent light tubes. However, the electrical circuitry is different in an LED tubular light source compared to in a fluorescent light tube in that the LED tube may provide a current path between the two end caps. As a result, installation of retrofitted LED tubular light sources may be a safety hazard as it is possible to first install one end cap in the mains connected fixture while having the other end cap still exposed and carrying a live potential on the connection pins of the exposed cap. Thus, the installer may touch the exposed end cap and get an electrical shock.
US2010/018178 discloses a suggestion on how the aforementioned safety issue may be alleviated by introducing a safety switch in the end cap of the LED tubular light source. However, a push-in safety switch according to US2010/018178 may in some cases be unintentionally engaged when the installer is pushing a first end of the tubular light source as a second end is inserted into the fixture, thereby exposing the installer to potential hazard as the unconnected end cap may then have a live potential. Furthermore, the installer may gain a false sense of security as the presence of a safety switch may make the installer believe that installation is safe in all circumstances.
Therefore, there is a need for an improved safety mechanism to improve the safety for the installer when installing retrofitted LED tubular light sources.